# HG changeset patch
# User Antoine Pitrou <solipsis@pitrou.net>
# Date 2013-09-07 19:20:00
# Node ID fd4f612f7cb6413940d4cf2052334cd23f60e042
# Parent  26ddce1a2a55809d430498f4ed1fa9594c390885

bundle: fix performance regression when bundling file changes (issue4031)

Somewhere before 2.7, a change [ec896f9e8894] was committed that
entailed a large performance regression when bundling (and therefore
remote cloning) repositories. For each file in the repository, it would
recompute the set of needed changesets even though it is the same for
all files. This computation would dominate bundle runtimes according to
profiler output (by 10x or more).

diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -354,11 +354,11 @@ class bundle10(object):
         progress(msgbundling, None)
 
         mfs.clear()
+        needed = set(cl.rev(x) for x in clnodes)
 
         def linknodes(filerevlog, fname):
             if fastpathlinkrev:
                 ln, llr = filerevlog.node, filerevlog.linkrev
-                needed = set(cl.rev(x) for x in clnodes)
                 def genfilenodes():
                     for r in filerevlog:
                         linkrev = llr(r)